1 
2 /*
3  *  ATI Mach64 CT/VT/GT/LT Support
4  */
5 
6 #include <linux/fb.h>
7 #include <linux/delay.h>
8 #include <asm/io.h>
9 #include <video/mach64.h>
10 #include "atyfb.h"
11 #ifdef CONFIG_PPC
12 #include <asm/machdep.h>
13 #endif
14 
15 #undef DEBUG
16 
17 static int aty_valid_pll_ct (const struct fb_info *info, u32 vclk_per, struct pll_ct *pll);
18 static int aty_dsp_gt       (const struct fb_info *info, u32 bpp, struct pll_ct *pll);
19 static int aty_var_to_pll_ct(const struct fb_info *info, u32 vclk_per, u32 bpp, union aty_pll *pll);
20 static u32 aty_pll_to_var_ct(const struct fb_info *info, const union aty_pll *pll);
21 
22 u8 aty_ld_pll_ct(int offset, const struct atyfb_par *par)
23 {
24 	u8 res;
25 
26 	/* write addr byte */
27 	aty_st_8(CLOCK_CNTL_ADDR, (offset << 2) & PLL_ADDR, par);
28 	/* read the register value */
29 	res = aty_ld_8(CLOCK_CNTL_DATA, par);
30 	return res;
31 }
32 
33 static void aty_st_pll_ct(int offset, u8 val, const struct atyfb_par *par)
34 {
35 	/* write addr byte */
36 	aty_st_8(CLOCK_CNTL_ADDR, ((offset << 2) & PLL_ADDR) | PLL_WR_EN, par);
37 	/* write the register value */
38 	aty_st_8(CLOCK_CNTL_DATA, val & PLL_DATA, par);
39 	aty_st_8(CLOCK_CNTL_ADDR, ((offset << 2) & PLL_ADDR) & ~PLL_WR_EN, par);
40 }
41 
42 /*
43  * by Daniel Mantione
44  *                                  <daniel.mantione@freepascal.org>
45  *
46  *
47  * ATI Mach64 CT clock synthesis description.
48  *
49  * All clocks on the Mach64 can be calculated using the same principle:
50  *
51  *       XTALIN * x * FB_DIV
52  * CLK = ----------------------
53  *       PLL_REF_DIV * POST_DIV
54  *
55  * XTALIN is a fixed speed clock. Common speeds are 14.31 MHz and 29.50 MHz.
56  * PLL_REF_DIV can be set by the user, but is the same for all clocks.
57  * FB_DIV can be set by the user for each clock individually, it should be set
58  * between 128 and 255, the chip will generate a bad clock signal for too low
59  * values.
60  * x depends on the type of clock; usually it is 2, but for the MCLK it can also
61  * be set to 4.
62  * POST_DIV can be set by the user for each clock individually, Possible values
63  * are 1,2,4,8 and for some clocks other values are available too.
64  * CLK is of course the clock speed that is generated.
65  *
66  * The Mach64 has these clocks:
67  *
68  * MCLK			The clock rate of the chip
69  * XCLK			The clock rate of the on-chip memory
70  * VCLK0		First pixel clock of first CRT controller
71  * VCLK1    Second pixel clock of first CRT controller
72  * VCLK2		Third pixel clock of first CRT controller
73  * VCLK3    Fourth pixel clock of first CRT controller
74  * VCLK			Selected pixel clock, one of VCLK0, VCLK1, VCLK2, VCLK3
75  * V2CLK		Pixel clock of the second CRT controller.
76  * SCLK			Multi-purpose clock
77  *
78  * - MCLK and XCLK use the same FB_DIV
79  * - VCLK0 .. VCLK3 use the same FB_DIV
80  * - V2CLK is needed when the second CRTC is used (can be used for dualhead);
81  *   i.e. CRT monitor connected to laptop has different resolution than built
82  *   in LCD monitor.
83  * - SCLK is not available on all cards; it is know to exist on the Rage LT-PRO,
84  *   Rage XL and Rage Mobility. It is know not to exist on the Mach64 VT.
85  * - V2CLK is not available on all cards, most likely only the Rage LT-PRO,
86  *   the Rage XL and the Rage Mobility
87  *
88  * SCLK can be used to:
89  * - Clock the chip instead of MCLK
90  * - Replace XTALIN with a user defined frequency
91  * - Generate the pixel clock for the LCD monitor (instead of VCLK)
92  */
93 
94  /*
95   * It can be quite hard to calculate XCLK and MCLK if they don't run at the
96   * same frequency. Luckily, until now all cards that need asynchrone clock
97   * speeds seem to have SCLK.
98   * So this driver uses SCLK to clock the chip and XCLK to clock the memory.
99   */
100 
101 /* ------------------------------------------------------------------------- */
102 
103 /*
104  *  PLL programming (Mach64 CT family)
105  *
106  *
107  * This procedure sets the display fifo. The display fifo is a buffer that
108  * contains data read from the video memory that waits to be processed by
109  * the CRT controller.
110  *
111  * On the more modern Mach64 variants, the chip doesn't calculate the
112  * interval after which the display fifo has to be reloaded from memory
113  * automatically, the driver has to do it instead.
114  */
115 
116 #define Maximum_DSP_PRECISION 7
117 static u8 postdividers[] = {1,2,4,8,3};
118 
119 static int aty_dsp_gt(const struct fb_info *info, u32 bpp, struct pll_ct *pll)
120 {
121 	u32 dsp_off, dsp_on, dsp_xclks;
122 	u32 multiplier, divider, ras_multiplier, ras_divider, tmp;
123 	u8 vshift, xshift;
124 	s8 dsp_precision;
125 
126 	multiplier = ((u32)pll->mclk_fb_div) * pll->vclk_post_div_real;
127 	divider = ((u32)pll->vclk_fb_div) * pll->xclk_ref_div;
128 
129 	ras_multiplier = pll->xclkmaxrasdelay;
130 	ras_divider = 1;
131 
132 	if (bpp>=8)
133 		divider = divider * (bpp >> 2);
134 
135 	vshift = (6 - 2) - pll->xclk_post_div;	/* FIFO is 64 bits wide in accelerator mode ... */
136 
137 	if (bpp == 0)
138 		vshift--;	/* ... but only 32 bits in VGA mode. */
139 
140 #ifdef CONFIG_FB_ATY_GENERIC_LCD
141 	if (pll->xres != 0) {
142 		struct atyfb_par *par = (struct atyfb_par *) info->par;
143 
144 		multiplier = multiplier * par->lcd_width;
145 		divider = divider * pll->xres & ~7;
146 
147 		ras_multiplier = ras_multiplier * par->lcd_width;
148 		ras_divider = ras_divider * pll->xres & ~7;
149 	}
150 #endif
151 	/* If we don't do this, 32 bits for multiplier & divider won't be
152 	enough in certain situations! */
153 	while (((multiplier | divider) & 1) == 0) {
154 		multiplier = multiplier >> 1;
155 		divider = divider >> 1;
156 	}
157 
158 	/* Determine DSP precision first */
159 	tmp = ((multiplier * pll->fifo_size) << vshift) / divider;
160 
161 	for (dsp_precision = -5;  tmp;  dsp_precision++)
162 		tmp >>= 1;
163 	if (dsp_precision < 0)
164 		dsp_precision = 0;
165 	else if (dsp_precision > Maximum_DSP_PRECISION)
166 		dsp_precision = Maximum_DSP_PRECISION;
167 
168 	xshift = 6 - dsp_precision;
169 	vshift += xshift;
170 
171 	/* Move on to dsp_off */
172 	dsp_off = ((multiplier * (pll->fifo_size - 1)) << vshift) / divider -
173 		(1 << (vshift - xshift));
174 
175 /*    if (bpp == 0)
176         dsp_on = ((multiplier * 20 << vshift) + divider) / divider;
177     else */
178 	{
179 		dsp_on = ((multiplier << vshift) + divider) / divider;
180 		tmp = ((ras_multiplier << xshift) + ras_divider) / ras_divider;
181 		if (dsp_on < tmp)
182 		dsp_on = tmp;
183 		dsp_on = dsp_on + (tmp * 2) + (pll->xclkpagefaultdelay << xshift);
184 	}
185 
186 	/* Calculate rounding factor and apply it to dsp_on */
187 	tmp = ((1 << (Maximum_DSP_PRECISION - dsp_precision)) - 1) >> 1;
188 	dsp_on = ((dsp_on + tmp) / (tmp + 1)) * (tmp + 1);
189 
190 	if (dsp_on >= ((dsp_off / (tmp + 1)) * (tmp + 1))) {
191 		dsp_on = dsp_off - (multiplier << vshift) / divider;
192 		dsp_on = (dsp_on / (tmp + 1)) * (tmp + 1);
193 	}
194 
195 	/* Last but not least:  dsp_xclks */
196 	dsp_xclks = ((multiplier << (vshift + 5)) + divider) / divider;
197 
198 	/* Get register values. */
199 	pll->dsp_on_off = (dsp_on << 16) + dsp_off;
200 	pll->dsp_config = (dsp_precision << 20) | (pll->dsp_loop_latency << 16) | dsp_xclks;
201 #ifdef DEBUG
202 	printk("atyfb(%s): dsp_config 0x%08x, dsp_on_off 0x%08x\n",
203 		__func__, pll->dsp_config, pll->dsp_on_off);
204 #endif
205 	return 0;
206 }
207 
208 static int aty_valid_pll_ct(const struct fb_info *info, u32 vclk_per, struct pll_ct *pll)
209 {
210 	u32 q;
211 	struct atyfb_par *par = (struct atyfb_par *) info->par;
212 	int pllvclk;
213 
214 	/* FIXME: use the VTB/GTB /{3,6,12} post dividers if they're better suited */
215 	q = par->ref_clk_per * pll->pll_ref_div * 4 / vclk_per;
216 	if (q < 16*8 || q > 255*8) {
217 		printk(KERN_CRIT "atyfb: vclk out of range\n");
218 		return -EINVAL;
219 	} else {
220 		pll->vclk_post_div  = (q < 128*8);
221 		pll->vclk_post_div += (q <  64*8);
222 		pll->vclk_post_div += (q <  32*8);
223 	}
224 	pll->vclk_post_div_real = postdividers[pll->vclk_post_div];
225 	//    pll->vclk_post_div <<= 6;
226 	pll->vclk_fb_div = q * pll->vclk_post_div_real / 8;
227 	pllvclk = (1000000 * 2 * pll->vclk_fb_div) /
228 		(par->ref_clk_per * pll->pll_ref_div);
229 #ifdef DEBUG
230 	printk("atyfb(%s): pllvclk=%d MHz, vclk=%d MHz\n",
231 		__func__, pllvclk, pllvclk / pll->vclk_post_div_real);
232 #endif
233 	pll->pll_vclk_cntl = 0x03; /* VCLK = PLL_VCLK/VCLKx_POST */
234 
235 	/* Set ECP (scaler/overlay clock) divider */
236 	if (par->pll_limits.ecp_max) {
237 		int ecp = pllvclk / pll->vclk_post_div_real;
238 		int ecp_div = 0;
239 
240 		while (ecp > par->pll_limits.ecp_max && ecp_div < 2) {
241 			ecp >>= 1;
242 			ecp_div++;
243 		}
244 		pll->pll_vclk_cntl |= ecp_div << 4;
245 	}
246 
247 	return 0;
248 }
249 
250 static int aty_var_to_pll_ct(const struct fb_info *info, u32 vclk_per, u32 bpp, union aty_pll *pll)
251 {
252 	struct atyfb_par *par = (struct atyfb_par *) info->par;
253 	int err;
254 
255 	if ((err = aty_valid_pll_ct(info, vclk_per, &pll->ct)))
256 		return err;
257 	if (M64_HAS(GTB_DSP) && (err = aty_dsp_gt(info, bpp, &pll->ct)))
258 		return err;
259 	/*aty_calc_pll_ct(info, &pll->ct);*/
260 	return 0;
261 }
262 
263 static u32 aty_pll_to_var_ct(const struct fb_info *info, const union aty_pll *pll)
264 {
265 	struct atyfb_par *par = (struct atyfb_par *) info->par;
266 	u32 ret;
267 	ret = par->ref_clk_per * pll->ct.pll_ref_div * pll->ct.vclk_post_div_real / pll->ct.vclk_fb_div / 2;
268 #ifdef CONFIG_FB_ATY_GENERIC_LCD
269 	if(pll->ct.xres > 0) {
270 		ret *= par->lcd_width;
271 		ret /= pll->ct.xres;
272 	}
273 #endif
274 #ifdef DEBUG
275 	printk("atyfb(%s): calculated 0x%08X(%i)\n", __func__, ret, ret);
276 #endif
277 	return ret;
278 }
279 
280 void aty_set_pll_ct(const struct fb_info *info, const union aty_pll *pll)
281 {
282 	struct atyfb_par *par = (struct atyfb_par *) info->par;
283 	u32 crtc_gen_cntl, lcd_gen_cntrl;
284 	u8 tmp, tmp2;
285 
286 	lcd_gen_cntrl = 0;
287 #ifdef DEBUG
288 	printk("atyfb(%s): about to program:\n"
289 		"pll_ext_cntl=0x%02x pll_gen_cntl=0x%02x pll_vclk_cntl=0x%02x\n",
290 		__func__,
291 		pll->ct.pll_ext_cntl, pll->ct.pll_gen_cntl, pll->ct.pll_vclk_cntl);
292 
293 	printk("atyfb(%s): setting clock %lu for FeedBackDivider %i, ReferenceDivider %i, PostDivider %i(%i)\n",
294 		__func__,
295 		par->clk_wr_offset, pll->ct.vclk_fb_div,
296 		pll->ct.pll_ref_div, pll->ct.vclk_post_div, pll->ct.vclk_post_div_real);
297 #endif
298 #ifdef CONFIG_FB_ATY_GENERIC_LCD
299 	if (par->lcd_table != 0) {
300 		/* turn off LCD */
301 		lcd_gen_cntrl = aty_ld_lcd(LCD_GEN_CNTL, par);
302 		aty_st_lcd(LCD_GEN_CNTL, lcd_gen_cntrl & ~LCD_ON, par);
303 	}
304 #endif
305 	aty_st_8(CLOCK_CNTL, par->clk_wr_offset | CLOCK_STROBE, par);
306 
307 	/* Temporarily switch to accelerator mode */
308 	crtc_gen_cntl = aty_ld_le32(CRTC_GEN_CNTL, par);
309 	if (!(crtc_gen_cntl & CRTC_EXT_DISP_EN))
310 		aty_st_le32(CRTC_GEN_CNTL, crtc_gen_cntl | CRTC_EXT_DISP_EN, par);
311 
312 	/* Reset VCLK generator */
313 	aty_st_pll_ct(PLL_VCLK_CNTL, pll->ct.pll_vclk_cntl, par);
314 
315 	/* Set post-divider */
316 	tmp2 = par->clk_wr_offset << 1;
317 	tmp = aty_ld_pll_ct(VCLK_POST_DIV, par);
318 	tmp &= ~(0x03U << tmp2);
319 	tmp |= ((pll->ct.vclk_post_div & 0x03U) << tmp2);
320 	aty_st_pll_ct(VCLK_POST_DIV, tmp, par);
321 
322 	/* Set extended post-divider */
323 	tmp = aty_ld_pll_ct(PLL_EXT_CNTL, par);
324 	tmp &= ~(0x10U << par->clk_wr_offset);
325 	tmp &= 0xF0U;
326 	tmp |= pll->ct.pll_ext_cntl;
327 	aty_st_pll_ct(PLL_EXT_CNTL, tmp, par);
328 
329 	/* Set feedback divider */
330 	tmp = VCLK0_FB_DIV + par->clk_wr_offset;
331 	aty_st_pll_ct(tmp, (pll->ct.vclk_fb_div & 0xFFU), par);
332 
333 	aty_st_pll_ct(PLL_GEN_CNTL, (pll->ct.pll_gen_cntl & (~(PLL_OVERRIDE | PLL_MCLK_RST))) | OSC_EN, par);
334 
335 	/* End VCLK generator reset */
336 	aty_st_pll_ct(PLL_VCLK_CNTL, pll->ct.pll_vclk_cntl & ~(PLL_VCLK_RST), par);
337 	mdelay(5);
338 
339 	aty_st_pll_ct(PLL_GEN_CNTL, pll->ct.pll_gen_cntl, par);
340 	aty_st_pll_ct(PLL_VCLK_CNTL, pll->ct.pll_vclk_cntl, par);
341 	mdelay(1);
342 
343 	/* Restore mode register */
344 	if (!(crtc_gen_cntl & CRTC_EXT_DISP_EN))
345 		aty_st_le32(CRTC_GEN_CNTL, crtc_gen_cntl, par);
346 
347 	if (M64_HAS(GTB_DSP)) {
348 		u8 dll_cntl;
349 
350 		if (M64_HAS(XL_DLL))
351 			dll_cntl = 0x80;
352 		else if (par->ram_type >= SDRAM)
353 			dll_cntl = 0xa6;
354 		else
355 			dll_cntl = 0xa0;
356 		aty_st_pll_ct(DLL_CNTL, dll_cntl, par);
357 		aty_st_pll_ct(VFC_CNTL, 0x1b, par);
358 		aty_st_le32(DSP_CONFIG, pll->ct.dsp_config, par);
359 		aty_st_le32(DSP_ON_OFF, pll->ct.dsp_on_off, par);
360 
361 		mdelay(10);
362 		aty_st_pll_ct(DLL_CNTL, dll_cntl, par);
363 		mdelay(10);
364 		aty_st_pll_ct(DLL_CNTL, dll_cntl | 0x40, par);
365 		mdelay(10);
366 		aty_st_pll_ct(DLL_CNTL, dll_cntl & ~0x40, par);
367 	}
368 #ifdef CONFIG_FB_ATY_GENERIC_LCD
369 	if (par->lcd_table != 0) {
370 		/* restore LCD */
371 		aty_st_lcd(LCD_GEN_CNTL, lcd_gen_cntrl, par);
372 	}
373 #endif
374 }
375 
376 static void aty_get_pll_ct(const struct fb_info *info, union aty_pll *pll)
377 {
378 	struct atyfb_par *par = (struct atyfb_par *) info->par;
379 	u8 tmp, clock;
380 
381 	clock = aty_ld_8(CLOCK_CNTL, par) & 0x03U;
382 	tmp = clock << 1;
383 	pll->ct.vclk_post_div = (aty_ld_pll_ct(VCLK_POST_DIV, par) >> tmp) & 0x03U;
384 
385 	pll->ct.pll_ext_cntl = aty_ld_pll_ct(PLL_EXT_CNTL, par) & 0x0FU;
386 	pll->ct.vclk_fb_div = aty_ld_pll_ct(VCLK0_FB_DIV + clock, par) & 0xFFU;
387 	pll->ct.pll_ref_div = aty_ld_pll_ct(PLL_REF_DIV, par);
388 	pll->ct.mclk_fb_div = aty_ld_pll_ct(MCLK_FB_DIV, par);
389 
390 	pll->ct.pll_gen_cntl = aty_ld_pll_ct(PLL_GEN_CNTL, par);
391 	pll->ct.pll_vclk_cntl = aty_ld_pll_ct(PLL_VCLK_CNTL, par);
392 
393 	if (M64_HAS(GTB_DSP)) {
394 		pll->ct.dsp_config = aty_ld_le32(DSP_CONFIG, par);
395 		pll->ct.dsp_on_off = aty_ld_le32(DSP_ON_OFF, par);
396 	}
397 }
398 
399 static int aty_init_pll_ct(const struct fb_info *info, union aty_pll *pll)
400 {
401 	struct atyfb_par *par = (struct atyfb_par *) info->par;
402 	u8 mpost_div, xpost_div, sclk_post_div_real;
403 	u32 q, memcntl, trp;
404 	u32 dsp_config, dsp_on_off, vga_dsp_config, vga_dsp_on_off;
405 #ifdef DEBUG
406 	int pllmclk, pllsclk;
407 #endif
408 	pll->ct.pll_ext_cntl = aty_ld_pll_ct(PLL_EXT_CNTL, par);
409 	pll->ct.xclk_post_div = pll->ct.pll_ext_cntl & 0x07;
410 	pll->ct.xclk_ref_div = 1;
411 	switch (pll->ct.xclk_post_div) {
412 	case 0:  case 1:  case 2:  case 3:
413 		break;
414 
415 	case 4:
416 		pll->ct.xclk_ref_div = 3;
417 		pll->ct.xclk_post_div = 0;
418 		break;
419 
420 	default:
421 		printk(KERN_CRIT "atyfb: Unsupported xclk source:  %d.\n", pll->ct.xclk_post_div);
422 		return -EINVAL;
423 	}
424 	pll->ct.mclk_fb_mult = 2;
425 	if(pll->ct.pll_ext_cntl & PLL_MFB_TIMES_4_2B) {
426 		pll->ct.mclk_fb_mult = 4;
427 		pll->ct.xclk_post_div -= 1;
428 	}
429 
430 #ifdef DEBUG
431 	printk("atyfb(%s): mclk_fb_mult=%d, xclk_post_div=%d\n",
432 		__func__, pll->ct.mclk_fb_mult, pll->ct.xclk_post_div);
433 #endif
434 
435 	memcntl = aty_ld_le32(MEM_CNTL, par);
436 	trp = (memcntl & 0x300) >> 8;
437 
438 	pll->ct.xclkpagefaultdelay = ((memcntl & 0xc00) >> 10) + ((memcntl & 0x1000) >> 12) + trp + 2;
439 	pll->ct.xclkmaxrasdelay = ((memcntl & 0x70000) >> 16) + trp + 2;
440 
441 	if (M64_HAS(FIFO_32)) {
442 		pll->ct.fifo_size = 32;
443 	} else {
444 		pll->ct.fifo_size = 24;
445 		pll->ct.xclkpagefaultdelay += 2;
446 		pll->ct.xclkmaxrasdelay += 3;
447 	}
448 
449 	switch (par->ram_type) {
450 	case DRAM:
451 		if (info->fix.smem_len<=ONE_MB) {
452 			pll->ct.dsp_loop_latency = 10;
453 		} else {
454 			pll->ct.dsp_loop_latency = 8;
455 			pll->ct.xclkpagefaultdelay += 2;
456 		}
457 		break;
458 	case EDO:
459 	case PSEUDO_EDO:
460 		if (info->fix.smem_len<=ONE_MB) {
461 			pll->ct.dsp_loop_latency = 9;
462 		} else {
463 			pll->ct.dsp_loop_latency = 8;
464 			pll->ct.xclkpagefaultdelay += 1;
465 		}
466 		break;
467 	case SDRAM:
468 		if (info->fix.smem_len<=ONE_MB) {
469 			pll->ct.dsp_loop_latency = 11;
470 		} else {
471 			pll->ct.dsp_loop_latency = 10;
472 			pll->ct.xclkpagefaultdelay += 1;
473 		}
474 		break;
475 	case SGRAM:
476 		pll->ct.dsp_loop_latency = 8;
477 		pll->ct.xclkpagefaultdelay += 3;
478 		break;
479 	default:
480 		pll->ct.dsp_loop_latency = 11;
481 		pll->ct.xclkpagefaultdelay += 3;
482 		break;
483 	}
484 
485 	if (pll->ct.xclkmaxrasdelay <= pll->ct.xclkpagefaultdelay)
486 		pll->ct.xclkmaxrasdelay = pll->ct.xclkpagefaultdelay + 1;
487 
488 	/* Allow BIOS to override */
489 	dsp_config = aty_ld_le32(DSP_CONFIG, par);
490 	dsp_on_off = aty_ld_le32(DSP_ON_OFF, par);
491 	vga_dsp_config = aty_ld_le32(VGA_DSP_CONFIG, par);
492 	vga_dsp_on_off = aty_ld_le32(VGA_DSP_ON_OFF, par);
493 
494 	if (dsp_config)
495 		pll->ct.dsp_loop_latency = (dsp_config & DSP_LOOP_LATENCY) >> 16;
496 #if 0
497 	FIXME: is it relevant for us?
498 	if ((!dsp_on_off && !M64_HAS(RESET_3D)) ||
499 		((dsp_on_off == vga_dsp_on_off) &&
500 		(!dsp_config || !((dsp_config ^ vga_dsp_config) & DSP_XCLKS_PER_QW)))) {
501 		vga_dsp_on_off &= VGA_DSP_OFF;
502 		vga_dsp_config &= VGA_DSP_XCLKS_PER_QW;
503 		if (ATIDivide(vga_dsp_on_off, vga_dsp_config, 5, 1) > 24)
504 			pll->ct.fifo_size = 32;
505 		else
506 			pll->ct.fifo_size = 24;
507 	}
508 #endif
509 	/* Exit if the user does not want us to tamper with the clock
510 	rates of her chip. */
511 	if (par->mclk_per == 0) {
512 		u8 mclk_fb_div, pll_ext_cntl;
513 		pll->ct.pll_ref_div = aty_ld_pll_ct(PLL_REF_DIV, par);
514 		pll_ext_cntl = aty_ld_pll_ct(PLL_EXT_CNTL, par);
515 		pll->ct.xclk_post_div_real = postdividers[pll_ext_cntl & 0x07];
516 		mclk_fb_div = aty_ld_pll_ct(MCLK_FB_DIV, par);
517 		if (pll_ext_cntl & PLL_MFB_TIMES_4_2B)
518 			mclk_fb_div <<= 1;
519 		pll->ct.mclk_fb_div = mclk_fb_div;
520 		return 0;
521 	}
522 
523 	pll->ct.pll_ref_div = par->pll_per * 2 * 255 / par->ref_clk_per;
524 
525 	/* FIXME: use the VTB/GTB /3 post divider if it's better suited */
526 	q = par->ref_clk_per * pll->ct.pll_ref_div * 8 /
527 		(pll->ct.mclk_fb_mult * par->xclk_per);
528 
529 	if (q < 16*8 || q > 255*8) {
530 		printk(KERN_CRIT "atxfb: xclk out of range\n");
531 		return -EINVAL;
532 	} else {
533 		xpost_div  = (q < 128*8);
534 		xpost_div += (q <  64*8);
535 		xpost_div += (q <  32*8);
536 	}
537 	pll->ct.xclk_post_div_real = postdividers[xpost_div];
538 	pll->ct.mclk_fb_div = q * pll->ct.xclk_post_div_real / 8;
539 
540 #ifdef CONFIG_PPC
541 	if (machine_is(powermac)) {
542 		/* Override PLL_EXT_CNTL & 0x07. */
543 		pll->ct.xclk_post_div = xpost_div;
544 		pll->ct.xclk_ref_div = 1;
545 	}
546 #endif
547 
548 #ifdef DEBUG
549 	pllmclk = (1000000 * pll->ct.mclk_fb_mult * pll->ct.mclk_fb_div) /
550 			(par->ref_clk_per * pll->ct.pll_ref_div);
551 	printk("atyfb(%s): pllmclk=%d MHz, xclk=%d MHz\n",
552 		__func__, pllmclk, pllmclk / pll->ct.xclk_post_div_real);
553 #endif
554 
555 	if (M64_HAS(SDRAM_MAGIC_PLL) && (par->ram_type >= SDRAM))
556 		pll->ct.pll_gen_cntl = OSC_EN;
557 	else
558 		pll->ct.pll_gen_cntl = OSC_EN | DLL_PWDN /* | FORCE_DCLK_TRI_STATE */;
559 
560 	if (M64_HAS(MAGIC_POSTDIV))
561 		pll->ct.pll_ext_cntl = 0;
562 	else
563 		pll->ct.pll_ext_cntl = xpost_div;
564 
565 	if (pll->ct.mclk_fb_mult == 4)
566 		pll->ct.pll_ext_cntl |= PLL_MFB_TIMES_4_2B;
567 
568 	if (par->mclk_per == par->xclk_per) {
569 		pll->ct.pll_gen_cntl |= (xpost_div << 4); /* mclk == xclk */
570 	} else {
571 		/*
572 		* The chip clock is not equal to the memory clock.
573 		* Therefore we will use sclk to clock the chip.
574 		*/
575 		pll->ct.pll_gen_cntl |= (6 << 4); /* mclk == sclk */
576 
577 		q = par->ref_clk_per * pll->ct.pll_ref_div * 4 / par->mclk_per;
578 		if (q < 16*8 || q > 255*8) {
579 			printk(KERN_CRIT "atyfb: mclk out of range\n");
580 			return -EINVAL;
581 		} else {
582 			mpost_div  = (q < 128*8);
583 			mpost_div += (q <  64*8);
584 			mpost_div += (q <  32*8);
585 		}
586 		sclk_post_div_real = postdividers[mpost_div];
587 		pll->ct.sclk_fb_div = q * sclk_post_div_real / 8;
588 		pll->ct.spll_cntl2 = mpost_div << 4;
589 #ifdef DEBUG
590 		pllsclk = (1000000 * 2 * pll->ct.sclk_fb_div) /
591 			(par->ref_clk_per * pll->ct.pll_ref_div);
592 		printk("atyfb(%s): use sclk, pllsclk=%d MHz, sclk=mclk=%d MHz\n",
593 			__func__, pllsclk, pllsclk / sclk_post_div_real);
594 #endif
595 	}
596 
597 	/* Disable the extra precision pixel clock controls since we do not use them. */
598 	pll->ct.ext_vpll_cntl = aty_ld_pll_ct(EXT_VPLL_CNTL, par);
599 	pll->ct.ext_vpll_cntl &= ~(EXT_VPLL_EN | EXT_VPLL_VGA_EN | EXT_VPLL_INSYNC);
600 
601 	return 0;
602 }
603 
604 static void aty_resume_pll_ct(const struct fb_info *info,
605 			      union aty_pll *pll)
606 {
607 	struct atyfb_par *par = info->par;
608 
609 	if (par->mclk_per != par->xclk_per) {
610 		/*
611 		* This disables the sclk, crashes the computer as reported:
612 		* aty_st_pll_ct(SPLL_CNTL2, 3, info);
613 		*
614 		* So it seems the sclk must be enabled before it is used;
615 		* so PLL_GEN_CNTL must be programmed *after* the sclk.
616 		*/
617 		aty_st_pll_ct(SCLK_FB_DIV, pll->ct.sclk_fb_div, par);
618 		aty_st_pll_ct(SPLL_CNTL2, pll->ct.spll_cntl2, par);
619 		/*
620 		 * SCLK has been started. Wait for the PLL to lock. 5 ms
621 		 * should be enough according to mach64 programmer's guide.
622 		 */
623 		mdelay(5);
624 	}
625 
626 	aty_st_pll_ct(PLL_REF_DIV, pll->ct.pll_ref_div, par);
627 	aty_st_pll_ct(PLL_GEN_CNTL, pll->ct.pll_gen_cntl, par);
628 	aty_st_pll_ct(MCLK_FB_DIV, pll->ct.mclk_fb_div, par);
629 	aty_st_pll_ct(PLL_EXT_CNTL, pll->ct.pll_ext_cntl, par);
630 	aty_st_pll_ct(EXT_VPLL_CNTL, pll->ct.ext_vpll_cntl, par);
631 }
632 
633 static int dummy(void)
634 {
635 	return 0;
636 }
637 
638 const struct aty_dac_ops aty_dac_ct = {
639 	.set_dac	= (void *) dummy,
640 };
641 
642 const struct aty_pll_ops aty_pll_ct = {
643 	.var_to_pll	= aty_var_to_pll_ct,
644 	.pll_to_var	= aty_pll_to_var_ct,
645 	.set_pll	= aty_set_pll_ct,
646 	.get_pll	= aty_get_pll_ct,
647 	.init_pll	= aty_init_pll_ct,
648 	.resume_pll	= aty_resume_pll_ct,
649 };
650